The objectives of this research are directed at characterization of human leukemia-lymphoma cells in the permanent cell lines and from the patients. The membrane phenotyping of leukemia-lymphoma cells are the major method for the study. Xenoantisera specific against cells in lymphoid-myeloid cell differentiation will be developed for their use in immunofluorescence test. Continuous effort at establishing more of unique leukemia-lymphoma cell lines will be made. Comparative membrane phenotyping study on leukemia-lymphoma cells in vitro and in vivo will be evaluated as a possible reflection of the normal hematopoietic cell differentiation. Clinical significance of the leukemia-associated antigens at disease presentation and during the therapy will be evaluated.